They expire soon to get you on the same schedule with all of the other engineers. Almost all states do this so that they process the renewals at the same time for efficiency.
Not sure on the PDH's required though, some states prorate and some say your exempt for the first renewal. If it didn't say in your letter, then I would contact the board to make sure. Best to know from them for sure rather than assume what somebody else tells you is correct in our opinion.